1. Field of the Invention
The present invention relates to a washing machine and, more particularly, to a washing machine exchanging heat between inner air discharged from a drum and external air supplied into the drum through a heat exchanger to enhance drying efficiency.
2. Description of the Related Art
Generally, a drum type washing machine is an appliance intended to carry out a washing operation by falling clothes during rotation through 360 degrees of a rotatable washing chamber, and it also carries out rinsing, dewatering and drying operations.
A drying operation of the washing machine is classified into a circulation drying operation circulating inner air discharged from a drum, and a non-circulation drying operation supplying external air into the drum to dry the clothes.
As shown in FIG. 1, a conventional washing machine of the non-circulation drying operation comprises a drum 1; a supplying duct 2 supplying external air into the drum 1; a circulating fan 3 provided at a portion of the supplying duct 2 and introducing the external air into the drum 1; a heater 4 heating the external air introduced into the supplying duct 2; a discharging duct 5 discharging inner air used in a drying operation outward; and a heat exchanger 6 exchanging heat between the external air passing through the supplying duct 2 and the inner air passing through the discharging duct 5.
The conventional washing machine may make the temperature of the external air supplied into the drum 1 increase so that power consumption of the heater 4 is decreased, and also make the temperature of the inner air discharged therefrom decrease. The conventional washing machine with this configuration is disclosed in Korean Patent Application No. 10-2000-0059274.
However, in the conventional washing machine the supplying duct 2 and the discharging duct 5 are disposed side by side so that a flow direction of the inner air is opposite to that of the external air.
Accordingly, it is difficult to enhance heat-exchange efficiency between the external air and the inner air through the heat exchanger 6.
Further, temperature and humidity of the internal air discharged outward are often higher than that of the external air in a building. Accordingly, though the temperature and the humidity of the internal air are decreased a little while the internal air passes through the heat exchanger, the temperature and the humidity of the internal air are, in some instances, still too high to discharge the air in a building.